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| United States Patent |
5,008,294
|
|
Neiss
, et al.
|
April 16, 1991
|
Methods of treating tumors with compositions of catecholic butanes
Abstract
The invention relates to methods useful in the treatment of benign,
premalignant and malignant solid tumors, especially those of the skin
comprising methods for the administration of pharmacologically active
compositions containing catecholic butanes. The invention also relates to
methods of preventing the occurence of tumors, and the use of catecholic
butanes as a sunscreening agent. The preferred catecholic butane is
nordihydroguaiaretic acid. The preferred methods of application of the
compositions containing catecholic butanes are by topical application and
intratumor injection.
| Inventors:
|
Neiss; Edward S. (Denver, CO);
Allen; Larry M. (Golden, CO)
|
| Assignee:
|
Chemex Pharmaceuticals, Inc. (Denver, CO)
|
| Appl. No.:
|
057481 |
| Filed:
|
June 3, 1987 |
| Current U.S. Class: |
514/731 |
| Intern'l Class: |
A61K 031/05 |
| Field of Search: |
514/727,731
|
References Cited
U.S. Patent Documents
| 3934034 | Jan., 1976 | Manning | 514/734.
|
| 4695590 | Sep., 1987 | Lippman | 514/724.
|
Other References
"Medicine Based on a Derivative of Pyrocatechol", Special Patent for
Medicine, No. 981,050 (France).
"Antipsoriatic Drugs as Inhibitors of Soybean Lipoxygenase, A Possible Mode
of Action", Jagadish C. Sircar, et al., Protagladins Leucotrienes and
Medicine, 1983, vol. II, 373-380.
Smart et al., Rocky Mount. Med. J., Nov. 1970, pp. 39-43.
Bhuvcineswaran et al., Biochem., 11: 85-91, 1972.
|
Primary Examiner: Rollins; John W.
Attorney, Agent or Firm: Kenyon & Kenyon
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of a copending Application Ser.
No. 052,120 filed May 4, 1987, now abandoned, which is a continuation of
Application Ser. No. 699,923 filed Feb. 11, 1985, now abandoned, which is
a continuation-in-part of Application Ser. No. 578,501 filed Apr. 9, 1984,
now abandoned, which is a continuation-in-part of Application Ser. No
465,631, filed Feb. 10, 1983, now abandoned, which is a
continuation-in-part of Application Ser. No. 365,781 filed Apr. 5, 1982,
now abandoned, which is a continuation-in-part of Application Ser. No.
49,886 filed June 19, 1979, now abandoned.
Claims
What is claimed is:
1. A method for inhibiting the growth of a tumor which comprises topically
administering to the situs of the tumor of a mammal in need of said
treatment an effective amount of a composition comprising at least 1
catecholic butane of the formula:
##STR3##
wherein R.sub.1 and R.sub.2 are independently H, lower alkyl, lower acyl,
or alkylene;
R.sub.3, and R.sub.4, R.sub.5, R.sub.6, R.sub.10, R.sub.11, R.sub.12 and
R.sub.13 are independently H or lower alkyl;
R.sub.7, R.sub.8 and R.sub.9 are independently H, hydroxy, lower alkoxy,
lower acyloxy, or any two adjacent groups together may be alkylene dioxy.
2. The method according to claim 1 wherein the composition contains 0.1-10
wt. % of said catecholic butane.
3. The method according to claim 1 wherein the catecholic butane is
nordihydroguaiaretic acid.
4. The method according to claim 1 wherein said catecholic butane contains
at least one lower alkyl ether derivative moiety.
5. The method according to claim 1 wherein said catecholic butane contains
at least one lower acyl esther derivative moiety.
6. The method according to claim 1, wherein lower alkyl is C.sub.1 -C.sub.6
alkyl, R.sub.3 and R.sub.4 are C.sub.1 -C.sub.3 alkyl and the lower acyl
is a C.sub.1 -C.sub.6 acyl.
7. The method according to claim 1, wherein the catecholic butane is
selected from the group consisting of
1,4-bis(3,4-dihydroxphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dihydroxyphenyl)butane; 1,4-bis(3,4-dimethoxyphenyl)-2,3
-dimethylbutane; 1,4-bis(3,4-diethoxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dipropoxyphenyl)-2,3-dimethylbutane;
1-(3,4-dihydroxyphenyl)-4-(3,4,5-trihydroxyphenyl) butane;
1,4-bis(3,4-diacetoxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dipropionyloxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dibutyroyloxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-divaleroyloxphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dipivaloyloxphenyl)-2,3-dimethylbutane; 1,4-bis
(3,4-dipivaloyloxyphenyl) butane;
1,4-bis(3,4-dineopentylcarboxylphenyl)-2,3-dimethylbutane; and
1-(3,4-dihydroxyphenyl)-4-phenylbutane; 1-(3,4-dihydroxyphenyl)-4-(2,5
dihydroxyphenyl) butane.
8. The method according to claim 1 wherein the composition includes a
pharmaceutically acceptable carrier.
9. The method according to claim 1 wherein said administering is
effectuated by means selected from the group consisting of administration
to the surface of the skin at the situs of the tumor and injection of the
composition into the interior or near vicinity of the tumor.
10. The method according to claim 1 wherein the tumor are selected from the
group consisting of equine sarcoid, equine papilloma, equine malignant
melanoma, equine squamous cell carcinoma, canine perianal adenoma, canine
mast cell carcinoma, canine breast adenocarcinoma and canine malignant
melanoma.
11. The method according to claim 10, wherein the catecholic butane is
nordihydroguaiaretic acid.
12. The method according to claim 11, wherein 10 nanomoles of composition
are applied to each milliliter of solid tumor.
13. The method according to claim 10 wherein said administering is
effectuated by means selected from the group consisting of topical
administration to the surface of the skin at the situs of the tumor and
injection of the composition into the interior or near vicinity of the
tumor.
14. The method according to claim 10 wherein said catecholic butane is
substantially nordihydroguaiaretic acid.
15. The method according to claim 1 wherein the tumor is selected from the
group consisting of malignant melanoma, mammary tumor, basal cell
carcinoma, squamous cell carcinoma, and epidermal tumors of the skin.
16. A method for treating tumors of the skin, which comprises administering
to the skin of a mammal in need of said treatment an effective amount of a
composition comprising at least one catecholic butane of the formula:
##STR4##
wherein R.sub.1 and R.sub.2 are independently H, lower alkyl, lower acyl
or alkylene;
R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.10, R.sub.11, R.sub.12 and
R.sub.13 are independently H or lower alkyl;
R.sub.7, R.sub.8 and R.sub.9 are independently H, hydroxy, lower alkoxy,
lower acyloxy, or any two adjacent groups may be alkylene dioxy.
17. The method according to claim 16 wherein the composition includes a
pharmaceutically acceptable carrier.
18. The method for treating a keratosis of the skin which comprises
administering to the skin of a mammal in need of said treatment at the
situs of the keratosis an effective amount of a composition comprising at
least one catecholic butane of the formula:
##STR5##
wherein R.sub.1 and R.sub.2 are independently H, lower alkyl or lower
acyl;
R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.10, R.sub.11, R.sub.12 and
R.sub.13 are independently H or lower alkyl; and
R.sub.7, R.sub.8 and R.sub.9 are independently H, hydroxy, lower alkoxy or
lower acyloxy.
19. The method according to claim 18 wherein the catecholic butane is
selected from the group consisting of nordihydroguaiaretic acid in any of
its racemic forms, nordihydroguaiaretic acid tetrapivalate,
nordihydroguaiaretic acid tetrapropionate and all optical configurations
thereof.
20. The method according to claim 19 wherein the catecholic butane is
nordihydroguaiaretic acid.
21. The method according to claim 18 wherein the composition contains
0.1-10 wt. % of said catecholic butane.
22. The method according to claim 18 wherein said catecholic butane
contains at least one lower alkyl ether derivative moiety.
23. The method according to claim 18 wherein said catecholic butane
contains at least one lower acyl ester derivative moiety.
24. The method according to claim 18, wherein lower alkyl is C.sub.1
-C.sub.6 alkyl, R.sub.3 and R.sub.4 are C.sub.1 -C.sub.3 alkyl and the
lower acyl is a C.sub.1 -C.sub.6 acyl.
25. The method according to claim 18, wherein the catecholic butane is
selected from the group consisting of
1,4-bis(3,4-dihydroxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dihydroxyphenyl)butane; 1,4-bis(3,4-dimethoxyphenyl)-2,3
-dimethylbutane; 1,4-bis(3,4-diethoxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dipropoxyphenyl)-2,3-dimethylbutane;
1-(3,4-dihydroxyphenyl)-4-(3,4,5-trihydroxyphenyl) butane;
1,4-bis(3,4-diacetoxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dipropionyloxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dibutyroyloxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-divaleroyloxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dipivaloyloxphenyl)-2,3-dimethylbutane; 1,4-bis
(3,4-dipivaloyloxyphenyl) butane;
1,4-bis(3,4-dineopentylcarboxylphenyl)-2,3-dimethylbutane; and
1-(3,4-dihydroxyphenyl)-4-phenylbutane; 1-(3,4-dihydroxyphenyl)-4-(2,5
dihydroxyphenyl) butane.
26. The method according to claim 18 wherein the composition includes a
pharmaceutically acceptable carrier.
27. The method according to claim 18 wherein the keratosis is actinic
keratosis.
28. A method for treating actinic keratosis which comprises administering
to the skin of a mammal in need of said treatment at the situs of the
actinic keratosis an effective amount of a composition comprising at least
one catecholic butane of the formula:
##STR6##
wherein R.sub.1 and R.sub.2 are independently H, lower alkyl, or lower
acyl and R.sub.1 and R.sub.2 together may be alkylene;
R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.10, R.sub.11, R.sub.12 and
R.sub.13 are independently H or lower alkyl; and
R.sub.7, R.sub.8 and R.sub.9 are independently H, hydroxy, lower alkoxy,
lower acyloxy, or any two adjacent groups may be aklylene dioxy.
29. The method according got claim 28 wherein the catecholic butane is
selected from the group consisting of nordihydroguaiaretic acid in any of
its racemic forms, nordihydroguaiaretic acid tetrapivalate,
nordihydroguaiaretic acid tetrapropionate and all optical configurations
thereof.
30. A method for treating actinic keratosis which comprises administering
to the skin of a mammal in need of said treatment at the situs of the
actinic keratosis an effective amount of a composition comprising
nordihydroguaiaretic acid.
31. A method for treating tumors of the skin which comprises administering
to the skin of a mammal in need of said treatment an effective amount of a
composition comprising at least one catecholic butane of the formula:
##STR7##
wherein R.sub.1 is H, lower alkyl or lower acyl, R.sub.2 is lower acyl and
R.sub.1 and R.sub.2 together may be alkylene;
R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.10, R.sub.11, R.sub.12 R.sub.13
are independently H or lower alkyl; and
R.sub.7, R.sub.8 and R.sub.9 are independently H, hydroxy, lower alkoxy or
lower acyloxy; or any two adjacent groups together may be alkylene dioxy.
32. A method for treating tumors of the skin which comprises administering
to the skin of a mammal in need of said treatment an effective amount of a
composition comprising at least one catecholic butane of the formula:
##STR8##
wherein R.sub.1 and R.sub.2 are independently H, lower alkyl or lower acyl
and R.sub.1 and R.sub.2 together may be alkylene;
R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.10, R.sub.11, R.sub.12 and
R.sub.13 are H; and
R.sub.7, R.sub.8 and R.sub.9 are independently H, hydroxy, lower alkoxy or
lower acyloxy; or any two adjacent groups together may be alkylene dioxy.
33. A method for treating tumors of the skin which comprises administering
to the skin of a mammal in need of said treatment an effective amount of a
composition comprising at least one catecholic butane of the formula:
##STR9##
wherein R.sub.1, R.sub.2, R.sub.7 and R.sub.8 are lower acyl; R.sub.3 and
R.sub.4 are methyl; and
R.sub.5, R.sub.6, R.sub.9, R.sub.10, R.sub.11, R.sub.12 and R.sub.13 are H.
34. The method for treating tumors of the skin according to claim 33
wherein the tumor is actinic keratosis.
Description
FIELD OF THE INVENTION
This invention relates to new methods of treating benign, premalignant and
malignant solid tumors, particularly those of the skin, comprising the
application to said solid tumors of the herein defined catecholic butanes
and pharmaceutical formulations containing said catecholic butanes. The
methods according to the invention are also effective in preventing the
occurrence of benign, premalignant and malignant solid tumors of the skin
when applied prophylactically to subjects exposed to a high risk of cancer
causing agents, for sensitization of tumors to X-ray radiation and for the
treatment of liver cancer. The methods according to the invention are also
useful in the treatment of diseases and disorders of the skin such as acne
and psoriasis, in aiding the healing of skin wounds and breaks in the skin
and for antiviral, antibacterial and antifungal uses.
BACKGROUND
Methods of treating premalignant and malignant growths of the skin have
often been traumatic. A common method of treating disorders such as
actinic keratosis has been the application of liquid nitrogen to destroy
the affected tissue. Epidermal tumors are commonly treated by physical
removal through surgery. A method which has been used in the past is
chemosurgery through the application of escharotic or fixative chemicals
such as zinc chloride. This method has not been found to be particularly
effective because of the physical discomfort associated with the use of
such materials. It also has the disadvantage of destroying both healthy
tissue and the diseased tissue. Neither has the use of known antitumor
drugs been found to be particularly effective in the treatment of skin
tumors since these drugs are commonly applied systemically resulting in
substantial side effects due to their toxicity.
The naturally occurring meso form of the catecholic butane,
nordihydroguaiaretic acid [meso-1,4-bis
(3,4-dihydroxyphenyl)-2,3-dimethylbutane] ("NDGA") is found in the
creosote bush, and its general structure (generic to all of its
stereoisomeric forms) is given in Formula (I).
##STR1##
The creosote bush was used for centuries to brew a tea which was the basis
for a folk remedy that called for drinking the tea to cure colds,
rheumatism and other ailments. However, this remedy has not proven to be
successful. NDGA was also used for years as an antioxidant to inhibit the
development of rancidity in the fats of food products and as a stabilizer
of pharmaceutical preparations, perfumary oils, rubber and other
industrial products.
C. R. Smart et al. in the Rocky Mountain Medical Journal, Nov. 1970, pp.
39-43, conducted clinical studies to ascertain the validity of an earlier
report of tumor regression in a melanoma of a patient taking "Chaparrel
Tea", which contains NDGA. In the clinical study conducted by Smart et
al., human cancer patients ingested either "Chapparrel Tea", an aqueous
extract of Larrea divericata containing NDGA, or doses of pure NDGA.
Although some positive results were observed, the authors advised against
treatment with "Chaparrel Tea" due to a significant number of reported
cases of tumor stimulation. This confirmed the earlier screening studies
of NDGA conducted by Leiter et al. of the Cancer Chemotherapy National
Service Center of the National Cancer Institute, which obtained negative
results when NDGA was tested against several types of cancer cells.
Surprisingly, it has now been discovered that catecholic butanes,
particularly nordihydroguaiaretic acid, and/or derivatives thereof as
defined herein, in a pharmaceutical composition, are effective in treating
benign, premalignant and malignant growths, preferably when directly
applied to the situs, without the detrimental side effects associated with
chemotherapy or chemosurgical techniques. The compositions provide
particularly advantageous results when applied topically to the afflicted
area of the skin, or injected into the growth. As disclosed in copending
application Ser. Nos. 699,923 and 924,620, such compositions are also
effective in treating disorders of the skin including acne and psoriasis,
in aiding in the healing of skin wounds and in alleviating bacterial,
viral and fungal infections when applied to the situs of the disorder. The
compositions are also useful in the treatment of warts.
SUMMARY OF THE INVENTION
This invention relates to methods useful in the treatment and prevention of
benign, premalignant and malignant solid tumors, especially those of the
skin, comprising the application of pharmaceutical formulations having a
catecholic butane of the formula:
##STR2##
wherein R.sub.1 and R.sub.2 are independently H, lower alkyl, lower acyl,
or alkylene;
R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.10, R.sub.11, R.sub.12 and
R.sub.13 are independently H or lower alkyl;
R.sub.7, R.sub.8 and R.sub.9 are independently H, hydroxy, lower alkoxy,
lower acyloxy, or any two adjacent groups together may be alkylene dioxy.
Alkylene dioxy generally means methylene (or substituted methylene) dioxy
or ethylene (or substituted ethylene) dioxy. Lower alkyl is intended to
generally mean C.sub.1 -C.sub.6 alkyl, and preferably R.sub.3 and R.sub.4
are C.sub.1 -C.sub.3 alkyl. Lower acyl is intended to generally mean
C.sub.1 -C.sub.6 acyl, with C.sub.2 -C.sub.6 acyl being preferred. It will
be appreciated by those skilled in this art that Formula II is directed to
both the phenolic compounds and the conventional esters and ethers
thereof.
The invention comprises a method of inhibiting the abnormal growth of
cells, such as malignant melanoma cells, human mammary tumor cells, and
human lung squamous cell carcinoma cells by contacting the cells with
pharmaceutical compositions adapted for topical, parenteral, subcutaneous,
or intralesional administration comprising, in admixture with a
pharmaceutically acceptable carrier, a catecholic butane of Formula (II).
Thus, the invention comprises methods for inhibiting the abnormal growth
or proliferation of cells in mammals which preferably comprise applying an
amount of said catecholic butane effective to inhibit said abnormal growth
directly to the situs of the abnormal growth of cells by topical
application or by injection into the interior or near vicinity of the
afflicted situs. The preferred compositions comprise nordihydroguaiaretic
acid and such compositions in combination with pharmaceutically acceptable
carriers.
In a further method of use, the invention comprises a method of preventing
the growth of benign, premalignant and malignant cells by prophylactically
applying said composition comprising catecholic butanes to a particular
body site which may be abnormally exposed to a cancer inducing stimulus.
In a further embodiment, this invention comprises the application of a
formulation comprising about 0.05 to about 20 weight percent of
substantially pure catecholic butane, NDGA in a preferred embodiment, in
combination with a toxicologically acceptable carrier.
DETAILED DESCRIPTION OF THE INVENTION
The term "afflicted situs or area" or similar language, as used herein,
refers to a localized area of pathology, infection, wound, lesion, or
abnormal cells, including tumors, and the surrounding area.
The term "applying" as used herein embraces both topical applications to a
surface of the afflicted situs and injection into the interior of the
situs.
The term "mammal" as used herein includes feline, canine, equine, bovine,
rodent and primate species, including cats, dogs, horses, rats, mice,
monkeys and humans. Other animals e.g., birds, can also be successfully
treated with the compositions of this invention.
The term "abnormal growth of cells" refers to benign, premalignant and
malignant cells. Examples of the former include the cells associated with
adenomas, papillomas, etc. Examples of premalignant cells include actinic
keratosis.
The term "escharotic" means a corrosive or caustic agent which is capable
of killing healthy, living cells.
The term "solid tumor" refers to tumors in which a plurality of tumor cells
are associated with one another, i.e. contiguous and localized within a
confined site. This is to be contrasted with "fluid" or "hematogenous"
tumors in which the tumor cells occur primarily as unassociated or
individual cells, e.g. leukemia. Solid tumors generally propagate on host
tissues such as the epithelial, the connective and supportive tissues as
well as other tissues located throughout the body. Examples of epithelial
tumors include papillomas such as verruca verruciformis and carcinomas
such as squamous cell carcinoma, basal cell carcinoma, adenoma,
adenocarcinoma, cystadenoma, cystadenocarcinoma and Bowenoid carcinoma.
Examples of supportive and connective tissue tumors include sarcomas and
their benign counterparts such as fibrosarcoma, fibroma, liposarcoma,
lipoma, chondrosarcoma, chondroma, leiomysarcoma, and leimyoma. Examples
of other tissue tumors include gliomas (brain tumors) and malignant
melanomas.
The term "pharmaceutically-acceptable carrier" refers to a material that is
non-toxic, generally inert and does not adversely affect the functionality
of the active ingredients.
The methods according to the invention comprising the use of catecholic
butanes are surprisingly effective in the treatment of a variety of solid
tumors and skin disorders, and are particularly effective when the
afflicted areas, or the areas having an abnormal exposure to cancer
inducing stimuli, are directly contacted with the instant compositions.
The methods according to the invention have unexpectedly been found to
provide improved restoration of integrity to injured tissue and cause the
regression, elimination or prevention of solid tumors arising from all
three embryonic tissue types, namely squamous cell carcinoma, e.g., lung
carcinoma, arising from the ectodermal layer; adenocarcinomas, e.g.
breast, renal and colon cancer, arising from the endodermal layer; and
melanoma and brain cancers, arising from the mesodermal layer.
More specifically, the methods of the instant invention have been found to
be effective against the following solid mammalian tumors: mouse
Sarcoma-180; human tumors including malignant melanoma, Sarcoma-180,
squamous cell carcinoma, lung squamous cell carcinoma, breast
adenocarcinoma, glioma, glioastrocytoma, renal-cell carcinoma, colon,
Bowenoid carcinoma and basal cell carcinoma; equine tumors including
papillomas, malignant melanoma, sarcoid and squamous cell carcinoma; and
canine tumors including squamous cell carcinoma, breast adenocarcinoma,
perianal adenoma, basal cell carcinoma and mast cell tumor.
The novel methods of this invention are particularly useful in the
treatment of keratoses, especially actinic keratosis and senile keratotic
lesions, as well as certain cutaneous tumor manifestations of otherwise
systemic diseases. The novel methods of the invention have also been found
to be effective against equine diseases such as sarcoid, papilloma,
malignant melanoma and squamous cell carcinoma, and against canine
diseases such as perianal adenoma, mast cell carcinoma, breast
adenocarcinoma and malignant melanoma.
The preferred catecholic butane according to the invention, NDGA, has been
found to be particularly effective against the following solid human
tumors: melanoma (B-16), lung squamous cell carcinoma (LX-1), and human
breast adenocarcinoma (MX-1).
It has also been discovered that the catecholic butanes, particularly NDGA,
when applied topically, enhance the X-ray radiation effectiveness of the
tumor cells without radiation toxicity to surrounding uninvolved skin.
Consequently, the catecholic butanes may be useful in the treatment of
cutaneous afflictions such as Kaposi's sarcoma.
The invention has also been found to be effective not only in eliminating
or ameliorating tumors, but in preventing their occurrence when applied
prophylactically. It has been observed that the catecholic butanes are
effective in reducing the potential and preventing tumor promotion and in
reducing the potential of tumor induction. Thus, the catecholic butanes,
e.g., NDGA, are not only effective in preventing cancer formation after
cancer induction, but also can be used to prevent cancer development in
industrial workers exposed to a carcinogenic agent. In this regard, it is
contemplated that the catecholic butanes may be applied prophylactically
to a site having abnormal risk to carcinogenic agents or stimuli.
To prevent the establishment of cancer, the catecholic butanes can be
formulated into creams and ointments or in cosmetic bases to be used
daily, preferably topically. The catecholic butanes can also be used
together with a sunscreen to prevent sunlight induction of cancer and
sunlight promotion of existing cancers. Surprisingly, the catecholic
butanes, particularly NDGA, have been shown to be effective sunscreening
agents. In this regard, NDGA has been shown to strongly absorb sunlight at
wavelengths known to produce sunburn. Thus, the catecholic butanes can be
used to block sunlight and thereby prevent sunlight induction of cancer or
promotion of existing cancers.
The methods according to the instant invention are also useful in
conjunction with surgery for removal of internal cancers to eradicate
residual tumor cells and to act as a prophylactic against local recurrence
and metastatic spread of the tumor. The instant compositions may be
applied to the effected area in lieu of surgery when there are cosmetic
considerations due to the normally improved appearance of healed situs
treated with the instant compositions compared to surgery alone.
The catecholic butanes useful in the methods of the instant invention,
particularly NDGA, have also been found to be effective in treating
hepatic and colon carcinoma. The catecholic butanes, when applied
parenterally or by injection, are excreted primarily through the liver and
gut, and therefore exert preferential cytotoxicity to tumors located in
those organs.
The catecholic butanes useful in the methods of the instant invention are
of the Formula (II), and are commonly available from Aldrich Chemical Co.,
Milwaukee, Wis. or can be synthesized by known methods. Illustrative
classes of compounds within the scope of Formula (II) are those wherein:
(a) one or more of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6,
R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12 and R.sub.13 are
H, e.g., those wherein R.sub.5 is H, R.sub.5 and R.sub.6 are H or R.sub.5,
R.sub.6 and R.sub.7 are H and R.sub.8 and R.sub.9 are OH or OR.sub.1;
(b) R.sub.3 and R.sub.4 each are CH.sub.3 or C.sub.2 H.sub.5 including
those wherein R.sub.5, R.sub.6 and R.sub.7 are H and/or R.sub.8 and
R.sub.9 are OH and OR.sub.1;
(c) R.sub.1 and R.sub.2 are lower acyl, e.g., hydrocarbonacyl, preferably,
alkanoyl, e.g., acetyl, propionyl, etc., including those of (a) and (b);
(d) R.sub.1 and R.sub.2 are alike and R.sub.8 and R.sub.9 are OR.sub.1,
including those of (a), (b) and (c); and
(e) The compound is in the form of a single optical isomer or a mixture of
such isomers, e.g., a racemic mixture, or diastereoisomers including each
of (a), (b), (c) and (d).
As used herein, lower alkyl represents, inter alia, methyl, ethyl,
n-propyl, isopropyl, n-butyl, iso-butyl, tertbutyl, n-pentyl, isopentyl,
n-hexyl, and the like.
Lower acyl represents groups having the general formula RCO--, e.g., acetyl
(CH.sub.3 CO--), propionyl (CH.sub.3 CH.sub.2 CO--), butyryl (CH.sub.3
CH.sub.2 CH.sub.2 CO--), and the like. When the catecholic butane compound
is named as a substituted phenyl, the corresponding groups are acetoxy
(CH.sub.3 CO.sub.2 --), propionyloxy (CH.sub.3 CH.sub.2 CO.sub.2 --), and
butyroyloxy (CH.sub.3 CH.sub.2 CH.sub.2 CO.sub.2 --).
Examples of catecholic butanes include the d-, 1-, racemic mixture of d-
and 1-, and meso-isomers of
1,4-bis(3,4-dihydroxyphenyl)-2,3-dimethylbutane; 1,4-bis
(3,4-dihydroxyphenyl)butane;
1,4-bis(3,4-dimethoxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-diethoxyphenyl)-2,3-dimethyl-butane;
1,4-bis(3,4-dipropoxyphenyl)-2,3-dimethylbutane;
1-(3,4-dihydroxyphenyl)-4-(3',4',5'-trihydroxyphenyl) butane;
1,4-bis(3,4-diacetoxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dibutyroyloxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-divaleroyloxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dipivaloyloxyphenyl)-2,3-dimethylbutane;
1,4-bis(3,4-dineopentylcarboxylphenyl)-2,3-dimethylbutane;
1-(3,4-dihydroxyphenyl)-4-phenylbutane and 1-(3,4-dihydroxyphenyl-4-(2,5
dihydroxyphenyl) butane. Mixtures of the Formula (II) catecholic butanes
may be used in the instant compositions.
The efficacious amount of catecholic butane used in the method of this
invention may be varied over a wide range. The typical range of the amount
of catecholic butane in the instant methods is between about 0.05 wt.% and
20 wt.% and preferably, the amount of catecholic butane applied according
to the invention ranges between about 1 wt.% and 10 wt.%. As used herein,
the weight percent in the formulations refers to the concentrations of
materials being effectively delivered to the treatment site.
Generally, the efficacious amount and concentration of the catecholic
butane to be applied are those which result in the composition exhibiting
the property or properties required in the treatment for which the
composition is being used, namely, anti-tumor activity. The preferred
amounts depend upon the particular condition being treated, the method of
delivery of the composition to the treatment site, e.g., topically or by
injection, the rate of delivery of the active ingredients to the treatment
site, and the number of applications of the formulation which can be used.
Preferred amounts for any specific application may be determined by normal
pharmacological screening methods used in the art. If desired, an excess
of the catecholic butane can be used as appropriate for the specific
condition being treated. It has been found that it is necessary to contact
the tumor cells with at least a threshold amount of catecholic butane to
observe an inhibition in growth of the neoplasm. This minimum amount has
been found to be greater than about 10 nanomoles of catecholic butane per
milliliter of tumor cells. Generally, preferred amounts of the catecholic
butanes with respect to two classes of tumors and exemplary application
amounts/rate are shown in Table I.
TABLE I
______________________________________
Preferred Amount
Exemplary Application
of Catecholic
Amount/Rate of Catechol
Treatment/Use
Butane Composition
______________________________________
Pre-Malignant
0.05 to 15 wt. %
Apply topically 100 mg/cm.sup.2
Tumors of catecholic
to tumor. Repeat
butane application when amount of
prior application falls
below about 1 mg/cm.sup.2.
Wound may be dressed until
healing is complete. Healing
period may extend for
several months. Repeat daily
Solid Epithelial
0.1 to 20 wt. %
as indicated by observation
Tumors of catecholic
of tumor size reduction
butane (i.e., if no reduction
in size after 10 days,
repeat 2-3 times daily; if
reduction in size is
observed, after 10 days,
repeat at daily intervals or
sooner if reduction in size
ceases to continue). Healing
period may extend for
several months. Alter-
natively, 0.1 ml. of com-
position may be injected
intralesionally at the tumor
site.
______________________________________
The instant compositions can be applied topically to or injected into the
treatment site, e.g., subcutaneously by injection. When used for topical
applications, the catecholic butane is usually formulated with a
pharmaceutically-acceptable carrier. The novel methods according to the
invention have been found to be particularly effective when applied
directly to the surface of the tumor or injected therein.
Carrier materials are well known in the pharmaceutical formulation art and
include those materials referred to as diluents or vehicles. The carrier
may include inorganic or organic materials and should have sufficient
viscosity to allow spreading of the composition and provide good adherence
to the tissue to which it is topically applied. Examples of such carriers
include, without limitation, polyols such as glycerol, propylene glycol,
polyethylene glycol, preferably of a molecular weight between about 400
and about 8000, suitable mixtures thereof, vegetable oils, and other
materials well known to those skilled in this art. The viscosity of the
formulation can be adjusted by methods well known in the art, for example,
by the use of a higher molecular weight polyethylene glycol.
In addition to the catecholic butane and carrier, the formulation can
contain pharmacologically-acceptable additives or adjuvants such as
antimicrobial agents, e.g. methyl, ethyl, propyl, and butyl esters of
para-hydroxybenzoic acid as well as chlorobutanol, phenol, ascorbic acid,
etc. The formulation can also contain thickening or gelling agents,
emulsifiers, wetting agents, coloring agents, buffers, stabilizers and
preservatives including antioxidants such as butylhydroxyanisole in
accordance with the practice of the art. The formulation can also contain
penetration enhancers such as dimethyl sulfoxide, long-chain alcohols such
as nonoxynol, long-chain carboxylic acids, propylene glycol,
N-(2-hydroxyethyl)pyrrolidone,1-dodecyl-azacycloheptan-2-one, and the
like. Depending on the method of application and the disease being
treated, it may be desirable to use absorption-delaying agents such as
aluminum monostearate and gelatin.
The composition of the formulation can be adjusted using components
well-known in the formulation art to provide a pharmaceutical formulation
which is a gel, cream, ointment, solid, liquid, semi-solid, etc. The
particular physical form of the formulation depends on the desired method
of treatment and the patient to be treated.
Typical formulations of the pharmaceutical compositions of this invention
are set forth in Table II.
TABLE II
______________________________________
Application
Form Formulation Grams
______________________________________
Ointment
Catecholic butane
(preferred amount: about 1-5
gr.)
Peg 400 4.2
Peg 8000 61.7
Water 19.0
Ascorbic acid 0.1
Gel Catecholic butane
(preferred amount: about 0.1-
2 gr.)
Standard denatured
12.0
alcohol
Propylene glycol
22.5
Water 53.4
Non-ionic surfactant
6.0
Xantham gum 4.0
Ascorbic acid 0.1
Cream Catecholic butane
(preferred amount: about 1-5
gr.)
Ascorbic acid 0.1
Benzyl alcohol 5.0
Propylene glycol
23.0
Water 35.4
Stearyl alcohol
7.0
Cetyl alcohol 4.5
White petrolatum
13.0
Poloxyl-40 stearate
7.0
Solid Catecholic butane
(preferred amount: 1-10 gr.)
Carnuba wax 8.9
Beeswax 13.3
Lanolin anhydrous
4.4
Cetyl alcohol 4.4
Ascorbic acid 0.1
Castor oil 57.7
Water 1.2
Injectible
Catecholic butane
(preferred range: 0.1-5 gr.)
Liquid Water 31.9
Glycerine 36.5
Glycine 1.5
Sodium ascorbate
0.1
Propylene glycol
25.0
______________________________________
For administration by injection, the compositions according to the
invention are formulated as solutions or suspensions having a low enough
viscosity to be injected. The composition suitable for injectable use must
be sterile and fluid to the extent that easy syringe injection exists. It
should also be stable under conditions of manufacture and storage and be
preserved against contamination by microorganisms. Preservatives include
alcohol, benzoic acid, sorbic acid, and methyl and propyl paraben with and
without propylene glycol. Additionally, the pH of the composition must be
within a range which does not result in tissue damage, namely, between
about 3-7.5.
The concentrations of active ingredients in a particular formulation
required to provide a particular effective dose may be determined by a
person skilled in the pharmaceutical formulation art based upon the
properties of a carrier and the particular additives introduced into the
formulation. It is contemplated that formulations can be prepared that
have significantly higher concentrations of catecholic butane depending
upon the carrier and additives being used. If the carrier substantially
retains the catecholic butane or releases it at a slow rate, the
concentrations of the catecholic butane in the formulation can be
substantially increased and in fact may have to be substantially increased
in order to provide an effective treatment. In practice, it is preferred
that a formulation contain the lowest concentrations of catecholic butane
which effectively treat the condition with the desired number of
applications, i.e., a lower effective dose rate can be tolerated if
multiple applications are used. This low concentration limit is dependent
upon the delivery effectiveness of the carrier vehicle. Preferably, the
catecholic butane comprises between about 1 and about 10 weight percent of
the formulation.
A preferred embodiment of the instant invention comprises compositions
containing NDGA, i.e., meso
1,4-bis(3,4-dihydroxyphenyl)-2,3-dimethylbutane. This composition has been
found to be particularly effective in treating solid tumors and actinic
keratosis. Although the effective concentration of nordihydroguaiaretic
acid delivered to the treatment site depends, inter alia, upon the carrier
and other additives included in the formulation, ordinarily the
concentration of NDGA in the formulation will range from about 1 to about
15 weight percent. These ranges are provided by way of description and not
by way of limitation since it is recognized that the concentration may be
adjusted over a wide range depending on the carrier material, number of
applications used, etc., as described hereinabove.
The pH of the formulation is important in assuring stability of the
catecholic butane as well as assuring that the formulation is
physiologically acceptable to the patient. Many of the catechols,
particularly nordihydroguaiaretic acid, are susceptible to oxidation, for
example, by air. Such oxidation can result in discoloration of the
formulation rendering it unacceptable for pharmaceutical use. These
catechols are more stable against oxidation at lower pH levels. Therefore,
it is preferred that if the formulation is to be exposed to oxidizing
conditions the pH be maintained below about 7.5 and preferably below about
6 in order to provide maximum stability for the catechol against
oxidation. However, if oxidizing conditions can be avoided, for example,
by storage of the formulation under an inert atmosphere such as nitrogen,
a higher pH can be used. The pH of the formulation may be maintained
through the use of toxicologically-acceptable buffers. Such buffers are
well known in the pharmaceutical formulation art, and include hydrochloric
acid buffer, acid phthalate buffer, phosphate buffer and citric
acid/sodium citrate buffer.
Alternately, antioxidants such as ascorbic acid, hydroxyquinone, sodium
bisulfite, meta bisulfite, etc. can be added to the formulation.
In topical applications the instant compositions are applied to the
affected area or afflicted situs of the patient. The term "topical" refers
herein to the surface of the epidermal tissue, especially the skin, the
surface of tumors on the skin which have been debrided or otherwise
modified, as well as sites from which solid tumors have been removed
either from the skin or internally.
In preparing a formulation suitable for topical application, the catecholic
butane is normally mixed with a suitable solvent. Examples of solvents
which are effective for this purpose include ethanol, acetone, acetic
acid, aqueous alkaline solutions, dimethyl sulfoxide, glycerine, glycerol,
propylene glycol, nonoxynol, ethyl ether, polyethylene glycol, etc.
Application by injection can be used for treatment of solid tumors in which
removal by surgery is not desired or for which surgery is not medically
advisable. In this procedure the instant composition is injected directly
into the tumorous cells.
The methods of the instant invention have also been found to be useful in
the treatment of lesions and draining wounds which show impaired healing.
As used herein the term "lesion" refers to any pathological or traumatic
discontinuity of tissue. A "wound" is a lesion which results from a bodily
injury caused by physical means. Lesions which do not readily heal can be
manifestations of conditions, diseases or infections, for example,
cutaneous ulcers, osteomyletis, acne vulgaris, draining fistulas, etc. Not
uncommonly, lesions do not heal properly and continue to drain which
results in discomfort to the patient and a continued threat of severe
infection. Such conditions in which tissue does not readily grow to heal
the lesion or wound can be the result of bacterial infection or other
causes not fully understood. Exposed areas created by the sloughing off of
necrotic matter, generally result in pus formation (suppuration).
Direct contact of the exposed area of the wound or lesion with the instant
compositions has been found in clinical studies to substantially aid the
healing process, possibly by inducing the formation of granulation tissue.
This promotion of healing has significant advantages, for example, in the
treatment of solid tumors directly or the situs from which such tumors
have been surgically removed in that healing is promoted concurrently with
inhibiting the growth of any tumor cells which might remain at the site of
surgery.
In determining the efficacy of a catecholic butane formulation in the
treatment of a tumor, initial screening is commonly done by the Human
Tumor Clonogenic Assay (HTCA). It has been reported that clinical
correlations form retrospective analysis and prospective clinical trials
with such clonogenic assays have indicated that there is a 60 to 70%
correlation between in vitro sensitivity and clinical response. The
studies have also indicated that there is a greater than 90%
correspondence between in vitro resistance and treatment failure. However,
the screening of new antitumor agents is still primarily being conducted
using a variety of tumor models in vivo. The National Cancer Institute is
currently using in vivo tumor models which include the L-1210 lymphocytic
leukemia, B-16, melanoma, S-180 Carcinoma, 3 transplantable murine tumors,
and the MX-1 human mammary tumor xenograph.
The following examples are included by way of illustration and not by way
of limitation. Unless otherwise indicated, the nordihydroguaiaretic acid
used in the instant Examples was the meso-isomer and is designated NDGA.
Other isomers are indicated, e.g., d,l-NDGA.
EXAMPLE I
The catecholic butane 1-(3,4-dihydroxyphenyl)-4-(2,3,4 -trihydroxyphenyl)
butane was prepared by the following procedure.
500 grams of 3,4-dimethoxydihydrocinnamic acid was suspended in 1.6 liters
of methanol containing 250 ml of 2,2-dimethoxypropane. To this mixture was
added dropwise a solution made by adding 20 ml. of acetyl chloride to 400
ml of methanol. The resulting mixture was stirred overnight at room
temperature and finally at reflux for one hour. The solvent was evaporated
to give a syrup in quantitative yield, 533 g.
To 912 ml. of lithium aluminum hydride (1M in THF) was added dropwise 213
g. of 3,4-dimethoxydihydrocinnamic acid methyl ester dissolved in 900 ml
of dry THF at such a rate as to maintain gentle reflux (5 hours). The
reaction mixture was stirred overnight at room temperature, cooled in an
ice bath and treated dropwise with ammonium chloride solution (saturated)
(104 ml) over a two hour period. After stirring for several hours, the
reaction mixture was diluted with 500 ml. of THF, filtered and the
filtrate evaporated in a vacuum to give 160 g. (86%) of a light yellow
oil.
3-(3,4-dimethoxyphenyl)propanol (202 g) was added to 218 ml of
triethylamine in one and half liters of methylene chloride. This solution
was cooled to -10.degree. C. in an ice salt bath and 87.6 ml. of
methanesulfonyl chloride was added dropwise over a one and a half hour
period while stirring rapidly. Stirring was continued for another hour and
the mixture was washed with 700 ml. of ice water, 700 ml. of 3N
hydrochloric acid, 700 ml. of saturated sodium bicarbonate and finally
with 700 ml. of brine. The organic phase was dried with sodium sulfate and
evaporated in a vacuum to give an orange oil in quantitative yield, 282 g.
3-(3,4-dimethoxyphenyl)propanol methanesulfonate, 282 g., (1.029 mol.);
KBr, 282 g. (2.37 mol.) and dicyclohexano-18-crown-6, 19.2 g. (0.01515
mol.) were stirred in reflixing acetonitrile, 2.8 liters (dried over 3A
molecular sieves) for 22 hours. The mixture was filtered and the filtrate
evaporated in a vacuum to give an orange oil, 267 g. The product could be
purified by vacuum distillation at 0.5 mm Hg, b.p.=113-116.degree. C.
3-(3,4-Dimethoxyphenyl)propyl bromide, 25.9 g., in 50 ml. of dry
tetrahydrofuran (dried by distillation from LAH) was placed in a dropping
funnel. Magnesium powder, 2.5 g., and a trace of iodine was placed in a
dry three neck flask with nitrogen inlet and reflux condenser. The
reaction started upon addition of the liquid reactant and reflux was
continued over a three hour period during which time the metal dissolved
in the stirred solution. The reaction was cooled and the volume made up to
200 ml. to form a 0.5M solution in dry THF.
2,3,4-Trimethoxybenzaldehyde, 1.96 g. (0.01 mole), dissolved in 20 ml. of
dry THF and 20 ml. of the 0.5M Grignard reagent from
3-(3,4-dimethoxyphenyl)propyl bromide in THF was added dropwise at ice
temperature. The mixture sat over night at room temperature. The solution
was evaporated in a vacuum and 20 ml. of ethanol was added carefully
followed by excess sodium borohydride. Refluxing for a few minutes
destroyed the yellow color of the small amounts of ketone and other
unsaturated impurities formed from oxidation of the product. Most of the
ethanol was evaporated and the residue partitioned between water and
ether, 50 ml. of each. The ether phase was dried over sodium sulfate and
evaporated to give 4.65 g. of a pale yellow oil.
The 4-(3,4-dimethoxyphenyl)-l-(2,3,4-trimethoxyphenyl)butanol, 3.65 g., was
treated with excess sodium hydride, 1 g., and methyl iodide, one ml, in 25
ml. of dry dimethylformamide during one hour of stirring. Water was added
carefully dropwise at first and finally 500 ml. of water was added. The
product was extracted three times with 50 ml. of chloroform and the
solvent evaporated to give a colorless crude oily product that can be used
in the next step without further purification.
About 100 ml of anhydrous ammonia was condensed into a three necked flask
with a dry ice condenser and dry ice bath. The flask was protected from
moisture with a soda-lime tube and flow of dry nitrogen. One gram of clean
sodium metal was dissolved in the liquid ammonia and the whole of the
crude product in 20 ml of dry tetrahydrofuran was added as quickly as
possible. The dark blue solution was stirred rapidly for twelve minutes
before enough methanol was added to destroy the blue color. Evaporation of
the solvent under a vacuum gave a thick residue to which 500 ml. of water
was added. The water solution was extracted twice with 50 ml. of
chloroform that left three grams of oily residue on evaporation.
Chromatography of this crude product on 300 g. of silica-gel using
chloroform as an eluate gave 2.3 of pure
1-(3,4-dimethoxyphenyl)-4-(2,3,4-trimethoxyphenyl) butane (one spot on
TLC).
A 1.15 g. sample of 1-(3,4-dimethoxyphenyl)-4-(2,3, 4-trimethoxyphenyl)
butane was refluxed for nine hours in 50 ml. of 48% hydrobromic acid under
an inert nitrogen atmosphere. Standing over the weekend allowed 641 mg. of
tan product to settle out in the freezer. This material was recrystallized
under inert atmosphere from methanol-water 1:20 to give light pink
crystals, m.p.=165-167.degree. C.
The following compounds were prepared by a similar procedure:
(a) 1-(3,4-Dihydroxyphenyl)-4-(3,4,5-trihydroxyphenyl)butane;
(b) 1-(3,4-Dihydroxyphenyl)-4-phenylbutane
(c) 1-(3,4-Dihydroxyphenyl-4-(2,5-dihydroxyphenyl) butane;
(d) 1,4-Di(3,4-dihydroxphenyl)-l,2,3,4-tetramethylbutane
(e) 1,4-Di(3,4-dihydroxyphenyl)-2-methyl-3-ethylbutane
(f) 1,4-Di(3,4-dihydroxyphenyl)-l-propyl-2-methyl-3-ethylbutane.
EXAMPLE 2
NDGA was evaluated for its effect on human mammary carcinoma MX-1 xenograft
in athymic nude NCr mice.
A 14 mg. fragment of the human mammary carcinoma MX-1 was planted
subcutaneously into the axillary region of mice with a puncture in the
inguinal region at day 0. Mice with tumors weighing no less than 75 mg.
and no more than 350 mg. were selected and pooled on day 1.
Tumored groups of mice were injected with a 0.1 ml. volume of the
appropriate test or vehicle control substance on day 1 only. Individual
body weights were recorded on day 1 and two times per week thereafter
until day 60, and individual tumors were measured with calipers on day 1,
and twice per week thereafter through day 60. Mean tumor weights were
calculated for each measurement day. Each day, change in mean tumor weight
was determined for both the test and control.
0.1 ml. of Compositions A through I were injected intratumorally on day 1
with NDGA as set forth in the table below:
______________________________________
Composition No. Mice % NDGA in Composition
______________________________________
A 6 1.53 .+-. 0.06
B 6 2.49 .+-. 0.08
C 6 3.41 .+-. 0.18
D 6 4.61 .+-. 0.34
E 6 6.36 .+-. 0.69
F 6 7.62 .+-. 0.17
G 6 9.44 .+-. 0.16
H 6 15.40 .+-. 0.40
I 6 18.40 .+-. 0.30
______________________________________
The relative size (T/C%) of the tumor in the treated versus untreated
animals was calculated as follows:
##EQU1##
Efficacy is indicated by T/C of less than 100%; the smaller the value, the
more effective the composition as an antitumor agent.
The activity and duration of action of composition I is shown below:
______________________________________
Relative Tumor
Day Animals Died
Size, T/C %
______________________________________
1 0 0.0
4 0 109.9
8 0 59.9
11 0 16.1
15 0 14.2
18 0 15.5
22 0 13.0
25 0 17.1
______________________________________
The results for each of the compositions on day 26 are set forth in table
2:
TABLE 2
______________________________________
Dose-response evaluation of
Antitumor activity of NDGA on Day 26
Tumor Wt. Relative Tumor
Composition
NDGA Dose % (grams) Size, T/C %
______________________________________
A 1.53 5121.0 112.0
B 2.49 5827.0 129.8
C 3.41 5071.5 110.3
D 4.61 3390.9 71.7
E 6.36 3249.4 70.5
F 7.62 2650.3 56.0
G 9.44 1650.1 32.7
H 15.40 955.5 16.8
I 18.40 942.0 17.1
______________________________________
EXAMPLE 3
The antiproliferative effect of NDGA on CMT-12 cultured canine breast
adenocarcinoma tumor cells was evaluated in clonogenic (cancer cell)
assays.
Single cell suspensions of tumor cells harvested from culture flasks were
exposed to the different compositions of NDGA for one hour at 37.degree. C
in liquid medium, and the cells were then washed twice, suspended in
agarose medium and plated and the number of colony forming cells were
determined. Results are expressed as percent inhibition of survival of
clonogenic cells in treated cultures relative to nontreated control
cultures. Significant anticancer activity was defined as>70% inhibition of
the survival of colony-forming (tumor) cells.
The results of the clonogenic assay using CMT 12 canine mammary carcinoma
cells are presented in Table 3.
TABLE 3
______________________________________
No. Tumor Colonies
%
Composition Surviving Inhibition
______________________________________
5 MicroMolar NDGA
229.7 .+-. 10.9
0
10 MicroMolar NDGA
173.3 .+-. 23.3
82.5
18 microMolar NDGA
190 .+-. 16.3
90.9
27 microMolar NDGA
40 .+-. 16.3
98.1
56 microMolar NDGA
3.3 .+-. 4.7 99.8
______________________________________
EXAMPLE 4
Compositions of NDGA were tested for their ability to inhibit in vitro
growth of the MC-1 equine sarcoid-derived cell line, in experiments
similar to those of Example 3.
Compositions containing NDGA were uniformly successful in inhibiting colony
growth over the duration of the assay, an effect which was especially
noticable at concentrations of 27 and 56 microMolar NDGA.
TABLE 4
______________________________________
Percentage Inhibition of Colony Growth
At Day 14
Amount NDGA % Inhibition
(MicroMolar)
Experiment and % Inhibition
(Mean)
______________________________________
#1 #2 #3
18 20.9 36.7 39.5 32.4
27 32.8 58.9 49.3 47.0
56 33 62.2 40.7 45.3
______________________________________
EXAMPLE 5
The antitumor effect of NDGA against the human lung tumor cell line LX-T
was determined utilizing a clonogenic assay.
The human lung tumor cell line, LX-T, which was derived from the solid
tumor, LX-1, was cultured in the standard medium RPMI-1640 +10% fetal calf
serum (FCS). A stock solution (10.sup.-2 M) of NDGA was prepared by
dissolving 32.04 mg of NDGA in 4 ml DMSO and 6 ml distilled H.sub.2 0.
Serial dilutions of the test stock solutions were made in 15 ml of
Ca.sup.2+ --and Mg.sup.2+ --free Hank's balanced salt solution (HBSS).
The LX-T cells were incubated in the presence of various amounts of NDGA,
and the antitumor effect was determined by measuring the DNA control of
the LX-T nuclei using DNA flow cytometric analysis with a DNA-specific
fluorochrome, 4', 6-diamidino-2-phenylindole (DAPI).
Table 5A shows the effective doses at different responses (ED.sub.x) where
x represents 50, 75, 90 or 95% cell growth inhibition.
TABLE 5A
______________________________________
Calculated ED.sub.x for NDGA
(MicroMolar .+-. SD)
______________________________________
ED(50) 17.6 .+-. 4.07
ED(75) 26.6 .+-. 12.11
ED(90) 41.1 .+-. 28.10
ED(95) 55.9 .+-. 46.79
______________________________________
For comparison, Table 5B lists the ED .sub.(50) for three known anticancer
drugs along with the ED.sub.(50) for NDGA.
TABLE 5B
______________________________________
ED(50)
Drug Name microMolar
______________________________________
5-FU 102.23
Adriamycin 25.6
Mutamycin 18.43
NDGA 17.6
______________________________________
EXAMPLE 6
The in vivo antitumor effect of NDGA at various survival levels was
determined using MX-1 (human breast adenocarcinoma) cells implanted
subcutaneously in the flank of nude mice.
Tumors which reached the 25-100 mm.sup.2 range were used for the
experiment. 0.1 ml of the test compound in solution was injected directly
into the tumor. The tumors were measured periodically to determine their
weight until 60 days after the initial treatment or all mice had died.
Mice which showed no evidence of tumors were kept for 60 days to evaluate
potential for tumor recurrence, at which time tumor characteristics, if
any, were recorded.
The effective doses (ED.sub.x) of NDGA at different response levels are
provided in Table 6.
TABLE 6
______________________________________
ED.sub.x (micromoles) for NDGA
Response
Level Micromoles
______________________________________
ED(50) 13.62
ED(75) 25.66
ED(90) 48.33
ED(95) 74.34
______________________________________
EXAMPLE 7
A composition containing 17.6% NDGA and 1% BHT in Pego 400 was tested for
antineoplastic activity in athymic mice implanted with human breast
adenocarcinoma, MX-1. Each animal was innoculated intradermally on the
dorsum near the nape of the neck with 0.5 ml of a MX-1 homogenate. The
animals were treated by topical application with the NDGA composition
after day 23. The results are given in Table 7.
TABLE 7
______________________________________
Tumor Free Tumor Re-
Test Composition 60 Days currence
______________________________________
17.6% NDGA/1% BHT
3/5 0
in PEGO 400
______________________________________
EXAMPLE 8
Compositions containing 4.4 wt/wt% of meso and DL NDGA were tested for
efficacy against the MX-1 tumor as in Example 7.
The results are set forth in Table 8.
TABLE 8
______________________________________
Tumor Free Tumor Re-
Organic Compound
60 Days currence
______________________________________
NDGA 4/5 0
dl-NDGA 4/5 0
______________________________________
EXAMPLE 9
Mice were exposed to dimethyl benzanthracene (DMBA), a classical tumor
inducer, and to phorbol ester (TPA), a classical tumor promoter, after
having been treated with NDGA.
Twenty mice were included in each of the following groups:
1. Positive control group: DMBA+TPA. Female SENCAR mice 6-8 weeks old
received a single topical application of 10 mg of DMBA in 0.2 ml of
acetone as the initiating agent. After one week, animals received twice
weekly applications of tumor promoter TPA in 0.1 ml of acetone. Tumor
formation was recorded weekly.
2. Antipromoting activity: DMBA+NDGA+TPA. 30 minutes prior to each
application of TPA animals received topical application of NDGA (9 mg.) in
0.2 ml of acetone.
3. Anticarcinogenic activity: NDGA+DMBA+TPA. For five consecutive days
animals received topical applications of NDGA (3 mg.) in 0.2 ml of
acetone. 24 hours after the last treatment with NDGA, animals received
DMBA and TPA exactly as in the positive control group.
NDGA was shown to nearly completely prevent TPA tumor promotion and to
significantly reduce the potential of tumor induction by DMBA.
EXAMPLE 10
The ability of NDGA to absorb harmful sunlight radiation was tested.
A solution of NDGA in methanol was demonstrated to absorb strongly at 2816
Angstroms in the ultraviolet region, a sunlight wavelength known to result
in sunburn.
Although the foregoing invention has been described in some detail by way
of illustration and example for purposes of clarity and understanding, it
will be obvious that certain changes and modifications may be practiced
within the scope of the invention, as limited only by the scope of the
appended claims.
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